B. corticulans is blackish-green in color
with axes (thalli) that are naked above and pinnately branched
above. The thallus of Bryopsis has vacuole (fluid-filled
region) that transverses through the center of the thallus. The
vacuole is membrane bound and supported by a cytoskeleton of actin
and microtubule filaments. Thus the chloroplasts and organelles
are forced to travel in a narrow region between the membrane and
the vacuole (stream-lined movement). This is probably why you can
see the chloroplasts so clearly in the pictures below (at 200X)
becuase the chloroplasts have all been pushed to the outside in
a narrow space between the vacuole and the membrane.

Bryopsis is a green algae and therefore
has chlorophylls a and b that give it its luscious green color,
as well as several accessory pigments including carotenes and xanthin.
Like other greens, it stores its food mainly as starch (carbohydrate).
Its chloroplasts can have pyrenoids (outpockets in in the thylakoid
membranes of chloroplasts), though the function of pyrenoids is
not clear. Bryopsis has a very thin external membrane that
is composed of pectin and cellulose.

Because Bryopsis is unicellular, damage to
the plant (which would be the entire cell) could be potentially
fatal, e.g. all the cytoplasm leaking out of the cell when it is
cut. A multicellular organism could localize the wound to one or
a few cells, but Bryopsis does not have that option. Luckily, Bryopsis as
well as other members in its family have evolved a way to "heal" themselves
when damaged (tears, cuts, dessication, etc.). When the membrane
is punctured, "clotting factors" (specific proteins,
organelles and chloroplasts) will actually aggregate at the site
of the wound and plug it up. WIthin 15-20 minutes, a gelatinous
envelope composed of polysaccharides and lipids develops around
the aggregates. A cell membrane and cell wall are subsequently
formed around the aggregate as well [6, 7].
This process somewhat resemebles the blood clotting process humans
undergo when we get cut.

This clotting process in Bryopsis is also
involved in vegetatively reproduction through abscission and fragmentation
of the plant. Sometimes, a separated fragment can become a plant
of its own (complete with ability to reproduce and everything)
because clotting will plug up the openings of the fragment. From
there, a rhizoid will develop at the base and the thallus will
continue to grow apically like the parent plant [6, 7].